Virtually all marine vessels (boats) of any size have seacocks, typically which are manually operated. A seacock is a flanged valve that is mounted directly to the inside of a boat hull to provide a leak proof joint around a discharge orifice from inside the hull to outside the hull. Many vessels have more than one seacock, in different sizes, for all different types of overboard discharge applications, and in most cases the seacocks are located in an area of the boat that is not easily accessible to the boat owner or operator. In normal use the seacocks remain in the open position and are closed only when the boat is not used for an extended period of time.
Although seacocks are normally kept open, and perhaps because of that, one of the most frequent mistakes common to marine vessels is to try and discharge through a seacock when it is closed. This is particularly unpleasant and disastrous where the seacock is connected up to a discharge pump which in turn is connected to a tank for holding sewage that has accumulated on the boat. If the discharge pump is actuated when the seacock connected to it is closed, damage to the pump, breakage of the flexible discharge hose connected between the pump and the seacock, and damage to check valves inside the pump, may all occur. Also if the pump is a positive displacement type (which is common) the motor may stall, creating a dangerous amperage overload that a fuse or circuit breaker may not properly prevent.
According to the present invention, a system is provided for either minimizing the possibility of operating the discharge pump when the seacock associated with it is closed, or positively preventing operation of the pump under those circumstances. By utilizing the invention, one of the most common errors in boat start-up operations can thus be avoided, with minimal additional expense.
According to one aspect of the present invention a sewage handling system for use on a boat is provided. The system comprises the following components: A seacock movable from a first, open, position allowing passage of liquid therethrough to a second, closed position precluding the passage of liquid therethrough. A sewage holding tank. A discharge pump. A flexible hose connecting the discharge pump to the seacock so that when the pump is activated the pump pumps sewage from the tank through the seacock. An electrical switch actuated in response to the position of the seacock. And, the electrical switch connected to the discharge pump to substantially prevent operation of the discharge pump if the seacock is in the second, closed, position. Preferably the switch is connected to allow operation of the pump only if the seacock is substantially in the completely open position.
The electrical switch preferably is waterproof, and meets marine vessel ignition prevention and electromagnetic compatibility requirements. Preferably the seacock is manually operated, having a manual handle that is movable between the open and closed positions, the handle actuating the switch in response to the movement thereof. For example the handle may be rotatable about an axis substantially perpendicular to the direction of passage of liquid through the seacock when open, and the switch actuator may be a radial extension of that handle. Preferably the system also comprises an indicator actuated in response to the seacock electrical position, such as at least one light emitting diode, and may also comprise an indicator connected to the discharge pump (again at least one light emitting diode) indicating when the discharge pump is operating.
According to another aspect of the present invention a boat is provided comprising: A hull. At least one seacock operatively attached to the hull and movable from a first, open, position allowing passage of liquid therethrough and through the hull therethrough to a second, closed, position precluding the passage of liquid therethrough. A sewage holding tank. A discharge pump. The sewage tank and discharge pump connected to the seacock so that when the seacock is in the first position thereof, and the pump is activated, the pump pumps sewage from the tank through the seacock. An electrical switch actuated in response to the position of the seacock. And, control circuitry connected to the seacock electrical switch and the discharge pump which prevents operation of the discharge pump if the seacock is in the second, closed, position.
The boat may further comprise a pump control electrical switch connected to the discharge pump and movable to a momentary manual position which requires operator activation of the pump, or an automatic position in which the pump operates automatically once sewage in the tank has reached a predetermined level. Indicators may be provided as described above, and the electrical switch and seacock may also have the characteristics as described above. The control circuitry may prevent operation of the discharge pump unless the seacock is in substantially the first, fully open, position.
According to another aspect of the present invention a boat is provided comprising: A hull. At least one seacock operatively attached to the hull and movable from a first, open, position allowing passage of liquid therethrough and through the hull therethrough to a second, closed, position precluding the passage of liquid therethrough. A sewage holding tank. A discharge pump. The sewage tank and discharge pump connected to the seacock so that when the seacock is in the first position thereof, and the pump is activated, the pump pumps sewage from the tank through the seacock. An electrical switch actuated in response to the position of the seacock. An indicator actuated in response to the seacock electrical switch position. And, an indicator connected to the discharge pump indicating when the discharge pump is operating. The details of the components, as well as the addition of an indicator, pump electrical control switch, etc., preferably are as described above.
It is the primary object of the present invention to effectively and simply minimize the possibility of operating a sewage discharge pump when the seacock associated therewith is closed. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.